1. Field of the Invention
This invention relates generally to dispensing closures for containers, and more particularly, to such closures which include a self-sealing spout, and also which may include a control member or overcap for operation of the spout.
2. Description of the Prior Art
Twist top and pull/push closures for containers are known in which a cap or spout with a central aperture cooperates with an upstanding post formed on a base to open or close the closure. The base is affixed to the mouth of a product container, such as a water bottle, and when the cap is moved, such as by twisting or pulling relative to the base, the post on the base is withdrawn from engagement with the aperture in the cap to permit product, such as water, in the container to be dispensed by passing through the aperture. After dispensing of the product is completed, the cap is returned to its closed position by reverse-twisting or pushing on the cap to re-engage the post in the aperture and thereby close the closure and prevent product from being dispensed from the container.
Examples of twist top and pull/push closures of the type referred to above are shown in the following U.S. patents which are owned by a wholly-owned subsidiary of the assignee of the present application: U.S. Pat. No. 5,328,063 issued Jul. 12, 1994 entitled xe2x80x9cVenting Closure Capxe2x80x9d; U.S. Pat. No. 4,967,941 issued Nov. 6, 1990 entitled xe2x80x9cTwist Lock Adjustable Metering Closure Cap.xe2x80x9d The disclosures of said two patents which illustrate structure and operational features of examples of twist top and pull/push closures hereby are incorporated herein by reference.
Attention also is directed to copending application Ser. No. 09/415,797, filed Oct. 11, 1999, entitled xe2x80x9cUniversal Base Pull/Push-Twist Closurexe2x80x9d, owned by the same assignee as the assignee of the present application, and disclosing a base similar to the base of the present invention. The disclosure of said copending application hereby is incorporated herein by reference.
The disclosure of U.S. Pat. No. 5,328,063 shows a pull/push closure in which a cap is mounted on its associated base and the closure is opened/closed by assertion of a pull/push force upon the cap with respect to the base. The disclosure of U.S. Pat. No. 4,967,941 shows a twist type closure in which the cap rides on a ramp formed in the associated base when the cap is twisted with respect to the base to effect the open/close operation of the cap with respect to the base. The disclosure of application Ser. No. 09/415,797 shows both pull/push and twist type closures which are movable to open/closed portions by either twisting or pull/push operation.
Interengagement between the aperture in the cap and the post formed on the base is intended to seal the closure and prevent product from being dispensed or escaping from the container on which the base is affixed. In instances where such closure are installed on liquid containers which retain a carbonated beverage product, such as carbonated water, it is desiralbe to incorporate a seal between the cap and the base which will prevent escape of the gas contained in such carbonated product for a maximum time period. Seal constructions of prior art closures have not been as successful as desired in preventing escape of carbonation gas from containers which retain such products so as to increase shelf life and to prevent such products from becoming stale. The seal construction of the present invention reduces the amount of torque required to open and close the closure. The seal construction also allows for greater interferences between the orifice in the cap and an interengaging plug on the base post which enables the sealing of greater pressure in the container which was not possible in prior art structures. Such greater interferences provide wider tolerance range to improve high volume manufacturing feasibility.
Additionally, it is desirable to provide an overcap component for such closures which protects the cap or spout from germ, dust and/or dirt contamination. Such an overcap also can provide a tamper-evident feature for such closures. An example of such an overcap is shown in U.S. Pat. No. 5,829,611 issued Nov. 3, 1998 entitled xe2x80x9cTamper-Evident Overcap,xe2x80x9d owned by a wholly-owned subsidiary of the Assignee of the present application. The disclosure of said patent hereby is incorporated herein by reference. In instances where such an overcap is used with a closure for a container retaining a carbonated beverage, the overcap serves an additional function of preventing carbonated liquid from spraying the user upon initial opening of the container. Further, it is desirable to provide an overcap which is capable of moving the cap over which the overcap is positioned relative to the base without the necessity for the user to touch the spout with his fingers, as in prior art constructions. For this purpose, it is desirable to provide an overcap which conforms in shape to the cap which is positioned under the overcap so as to facilitate movement of the cap to its open position upon movement of the overcap.
The invention is characterized by a closure including a cap movable with respect to its associated base between a closed sealed position and an open unsealed position in which product can be dispensed from a container upon which the base is secured. A generally U-shaped flange formed of resilient material such as plastic is positioned about the peripheral opening of an aperture formed in the cap which moves adjacent to a plug formed on the upstanding post of the associated base of the closure. One end of the U-shaped flange is secured to the aperture opening and the other end forms a terminal free end. The flange is in interference engagement with the plug when the cap is moved to its closed position. When so engaged, the terminal free end of the flange is moved into compression engagement with the wall of the plug. Also, the entire flange is moved to be spaced a greater circumferential distance about the plug than when the cap was in open or unsealed disposition with respect to the plug. Such spacing of the resilient flange adds or contributes to the sealing pressure of the flange about the plug.
The invention also is characterized, alternately, by a removable overcap positioned upon said base and disposed over the cap. The overcap preferably has an interior configuration which conforms to the exterior configuration of the cap to facilitate movement of the cap to open unsealed position without touching of the cap when the overcap is moved.
Various objects and advantages of the invention will become apparent in accordance with the above and ensuing disclosure in which the preferred embodiments are described in detail in the specification and illustrated in the accompanying drawings. It is contemplated that minor variations may occur to persons skilled in the art without departing from the scope or sacrificing any of the advantages of the invention.